Här är en uppdelning:
* The Tilt: The Moon's orbital plane is tilted about 5 degrees relative to the Earth's orbital plane (the ecliptic). Detta innebär att månen under de flesta nya och fulla månar är antingen över eller under jordens bana plan, så att solen, jorden och månen inte är perfekt.
* Eclipse Conditions: For a solar eclipse to occur, the Moon must pass directly between the Sun and Earth, casting its shadow on Earth. For a lunar eclipse, the Earth must pass directly between the Sun and Moon, casting its shadow on the Moon.
* The Nodes: The points where the Moon's orbit crosses the ecliptic are called the "nodes." Eclipses can only happen when the new or full moon coincides with one of these nodes.
* The Saros Cycle: Eclipses occur in a predictable pattern, known as the Saros cycle, which is about 18 years, 11 days, and 8 hours. This cycle accounts for the slight shift in the alignment of the Sun, Earth, and Moon that happens over time.
Sammanfattningsvis:
The tilt of the Moon's orbit means that the Sun, Earth, and Moon are not aligned perfectly during most new and full moons. Only when the new or full moon happens near one of the nodes can an eclipse occur. The Saros cycle helps us predict when these alignments will happen.
